Lawmakers who back natural-gas exports are trying to woo skeptical Democrats by arguing the sales would boost American power at the expense of Russia and Iran.

Russia has long dominated the market for natural gas in the Eastern hemisphere, with Iran being another major supplier. But booming production in the United States presents an opportunity to undercut those countries by selling more natural gas abroad, including to allies like Japan and India, boosters say.

Supporters of increased exports are increasingly citing the geopolitical benefits as they try to win over Democrats, many of whom fear shipping more natural gas abroad would cause price increases back home.